There are many exercising methods and machines in the art for developing muscular performance by dynamic loading of body parts in particular patterns over a movement cycle or exercise stroke, such as punching bags, bench presses, bicycles, rowing machines, and programmed exercise devices typified by such U.S. patents as E. R. Flavell, et al. 4,184,678, Jan 22, 1980; R. F. Bradley, 4,138,106, Feb 6, 1979; S. Owens, 4,934,692, Jun 19, 1990; and J. W. Brooker, 4,609,189, Sep. 2, 1986. However, these devices all have as a goal the development of muscular performance over a sustained movement stroke or cycle.